chan_iax2.c

/*
 * Asterisk -- A telephony toolkit for Linux.
 *
 * Implementation of Inter-Asterisk eXchange Version 2
 *
 * Copyright (C) 2003 - 2005, Digium, Inc.
 *
 * Mark Spencer <markster@digium.com>
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License
 */

#include "asterisk.h"

ASTERISK_FILE_VERSION(__FILE__, "$Revision$")

#include "asterisk/lock.h"
#include "asterisk/frame.h" 
#include "asterisk/channel.h"
#include "asterisk/logger.h"
#include "asterisk/module.h"
#include "asterisk/pbx.h"
#include "asterisk/sched.h"
#include "asterisk/io.h"
#include "asterisk/config.h"
#include "asterisk/options.h"
#include "asterisk/cli.h"
#include "asterisk/translate.h"
#include "asterisk/md5.h"
#include "asterisk/cdr.h"
#include "asterisk/crypto.h"
#include "asterisk/acl.h"
#include "asterisk/manager.h"
#include "asterisk/callerid.h"
#include "asterisk/app.h"
#include "asterisk/astdb.h"
#include "asterisk/musiconhold.h"
#include "asterisk/features.h"
#include "asterisk/utils.h"
#include "asterisk/causes.h"
#include "asterisk/localtime.h"
#include "asterisk/aes.h"
#include "asterisk/dnsmgr.h"
#include "asterisk/devicestate.h"
#include "asterisk/netsock.h"

#include <sys/mman.h>
#include <arpa/inet.h>
#include <dirent.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <sys/time.h>
#include <sys/signal.h>
#include <signal.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <netdb.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <regex.h>
#ifdef IAX_TRUNKING
#include <sys/ioctl.h>
#ifdef __linux__
#include <linux/zaptel.h>
#else
#include <zaptel.h>
#endif /* __linux__ */
#endif
#include "iax2.h"
#include "iax2-parser.h"
#include "iax2-provision.h"

/* Define NEWJB to use the new channel independent jitterbuffer,
 * otherwise, use the old jitterbuffer */
#define NEWJB

#ifdef NEWJB
#include "../jitterbuf.h"
#endif

#ifndef IPTOS_MINCOST
#define IPTOS_MINCOST 0x02
#endif

#ifdef SO_NO_CHECK
static int nochecksums = 0;
#endif

/*
 * Uncomment to try experimental IAX bridge optimization,
 * designed to reduce latency when IAX calls cannot
 * be trasnferred -- obsolete
 */

/* #define BRIDGE_OPTIMIZATION  */


#define PTR_TO_CALLNO(a) ((unsigned short)(unsigned long)(a))
#define CALLNO_TO_PTR(a) ((void *)(unsigned long)(a))

#define DEFAULT_RETRY_TIME 1000
#define MEMORY_SIZE 100
#define DEFAULT_DROP 3
/* Flag to use with trunk calls, keeping these calls high up.  It halves our effective use
   but keeps the division between trunked and non-trunked better. */
#define TRUNK_CALL_START	0x4000

#define DEBUG_SUPPORT

#define MIN_REUSE_TIME		60	/* Don't reuse a call number within 60 seconds */

/* Sample over last 100 units to determine historic jitter */
#define GAMMA (0.01)

static struct ast_codec_pref prefs;

static const char desc[] = "Inter Asterisk eXchange (Ver 2)";
static const char tdesc[] = "Inter Asterisk eXchange Driver (Ver 2)";
static const char channeltype[] = "IAX2";

static char context[80] = "default";

static char language[MAX_LANGUAGE] = "";
static char regcontext[AST_MAX_CONTEXT] = "";

static int max_retries = 4;
static int ping_time = 20;
static int lagrq_time = 10;
static int maxtrunkcall = TRUNK_CALL_START;
static int maxnontrunkcall = 1;
static int maxjitterbuffer=1000;
#ifdef NEWJB
static int resyncthreshold=1000;
static int maxjitterinterps=10;
#endif
static int jittershrinkrate=2;
static int trunkfreq = 20;
static int send_trunktimestamps = 1;
static int authdebug = 1;
static int autokill = 0;
static int iaxcompat = 0;

static int iaxdefaultdpcache=10 * 60;	/* Cache dialplan entries for 10 minutes by default */

static int iaxdefaulttimeout = 5;		/* Default to wait no more than 5 seconds for a reply to come back */

static int tos = 0;

static int expirey = IAX_DEFAULT_REG_EXPIRE;

static int timingfd = -1;				/* Timing file descriptor */

static struct ast_netsock_list *netsock;
static int defaultsockfd = -1;

static int usecnt;
AST_MUTEX_DEFINE_STATIC(usecnt_lock);

int (*iax2_regfunk)(char *username, int onoff) = NULL;

/* Ethernet, etc */
#define IAX_CAPABILITY_FULLBANDWIDTH 	0xFFFF
/* T1, maybe ISDN */
#define IAX_CAPABILITY_MEDBANDWIDTH 	(IAX_CAPABILITY_FULLBANDWIDTH & 	\
							~AST_FORMAT_SLINEAR & 	\
							~AST_FORMAT_ULAW & 	\
							~AST_FORMAT_ALAW) 
/* A modem */
#define IAX_CAPABILITY_LOWBANDWIDTH		(IAX_CAPABILITY_MEDBANDWIDTH & 	\
							~AST_FORMAT_G726 & 	\
							~AST_FORMAT_ADPCM)

#define IAX_CAPABILITY_LOWFREE		(IAX_CAPABILITY_LOWBANDWIDTH & 		\
							 ~AST_FORMAT_G723_1)


#define DEFAULT_MAXMS		2000		/* Must be faster than 2 seconds by default */
#define DEFAULT_FREQ_OK		60 * 1000	/* How often to check for the host to be up */
#define DEFAULT_FREQ_NOTOK	10 * 1000	/* How often to check, if the host is down... */

static	struct io_context *io;
static	struct sched_context *sched;

static int iax2_capability = IAX_CAPABILITY_FULLBANDWIDTH;

static int iax2_dropcount = DEFAULT_DROP;

static int iaxdebug = 0;

static int iaxtrunkdebug = 0;

static int test_losspct = 0;
#ifdef IAXTESTS
static int test_late = 0;
static int test_resync = 0;
static int test_jit = 0;
static int test_jitpct = 0;
#endif /* IAXTESTS */

static char accountcode[AST_MAX_ACCOUNT_CODE];
static int amaflags = 0;
static int delayreject = 0;
static int iax2_encryption = 0;

static struct ast_flags globalflags = {0};

static pthread_t netthreadid = AST_PTHREADT_NULL;

#define IAX_STATE_STARTED		(1 << 0)
#define IAX_STATE_AUTHENTICATED 	(1 << 1)
#define IAX_STATE_TBD			(1 << 2)

struct iax2_context {
	char context[AST_MAX_CONTEXT];
	struct iax2_context *next;
};

#define IAX_HASCALLERID		(1 << 0)	/* CallerID has been specified */
#define IAX_DELME		(1 << 1)	/* Needs to be deleted */
#define IAX_TEMPONLY		(1 << 2)	/* Temporary (realtime) */
#define IAX_TRUNK		(1 << 3)	/* Treat as a trunk */
#define IAX_NOTRANSFER		(1 << 4)	/* Don't native bridge */
#define IAX_USEJITTERBUF	(1 << 5)	/* Use jitter buffer */
#define IAX_DYNAMIC		(1 << 6)	/* dynamic peer */
#define IAX_SENDANI		(1 << 7)	/* Send ANI along with CallerID */
#define IAX_MESSAGEDETAIL	(1 << 8)	/* Show exact numbers */
#define IAX_ALREADYGONE		(1 << 9)	/* Already disconnected */
#define IAX_PROVISION		(1 << 10)	/* This is a provisioning request */
#define IAX_QUELCH		(1 << 11)	/* Whether or not we quelch audio */
#define IAX_ENCRYPTED		(1 << 12)	/* Whether we should assume encrypted tx/rx */
#define IAX_KEYPOPULATED 	(1 << 13)	/* Whether we have a key populated */
#define IAX_CODEC_USER_FIRST 	(1 << 14) 	/* are we willing to let the other guy choose the codec? */
#define IAX_CODEC_NOPREFS 	(1 << 15) 	/* Force old behaviour by turning off prefs */
#define IAX_CODEC_NOCAP 	(1 << 16) 	/* only consider requested format and ignore capabilities*/
#define IAX_RTCACHEFRIENDS 	(1 << 17) 	/* let realtime stay till your reload */
#define IAX_RTNOUPDATE 		(1 << 18) 	/* Don't send a realtime update */
#define IAX_RTAUTOCLEAR 	(1 << 19) 	/* erase me on expire */ 
#define IAX_FORCEJITTERBUF	(1 << 20)	/* Force jitterbuffer, even when bridged to a channel that can take jitter */ 
#define IAX_RTIGNOREREGEXPIRE	(1 << 21)

static int global_rtautoclear = 120;

static int reload_config(void);
static int iax2_reload(int fd, int argc, char *argv[]);


struct iax2_user {
	char name[80];
	char secret[80];
	char dbsecret[80];
	int authmethods;
	int encmethods;
	char accountcode[AST_MAX_ACCOUNT_CODE];
	char inkeys[80];				/* Key(s) this user can use to authenticate to us */
	char language[MAX_LANGUAGE];
	int amaflags;
	unsigned int flags;
	int capability;
	char cid_num[AST_MAX_EXTENSION];
	char cid_name[AST_MAX_EXTENSION];
	struct ast_codec_pref prefs;
	struct ast_ha *ha;
	struct iax2_context *contexts;
	struct iax2_user *next;
	struct ast_variable *vars;
};

struct iax2_peer {
	char name[80];
	char username[80];		
	char secret[80];
	char dbsecret[80];
	char outkey[80];				/* What key we use to talk to this peer */
	char context[AST_MAX_CONTEXT];			/* For transfers only */
	char regexten[AST_MAX_EXTENSION];		/* Extension to register (if regcontext is used) */
	char peercontext[AST_MAX_EXTENSION];		/* Context to pass to peer */
	char mailbox[AST_MAX_EXTENSION];		/* Mailbox */
	struct ast_codec_pref prefs;
	struct ast_dnsmgr_entry *dnsmgr;		/* DNS refresh manager */
	struct sockaddr_in addr;
	int formats;
	int sockfd;					/* Socket to use for transmission */
	struct in_addr mask;
	unsigned int flags;

	/* Dynamic Registration fields */
	struct sockaddr_in defaddr;			/* Default address if there is one */
	int authmethods;				/* Authentication methods (IAX_AUTH_*) */
	int encmethods;					/* Encryption methods (IAX_ENCRYPT_*) */
	char inkeys[80];				/* Key(s) this peer can use to authenticate to us */

	/* Suggested caller id if registering */
	char cid_num[AST_MAX_EXTENSION];		/* Default context (for transfer really) */
	char cid_name[AST_MAX_EXTENSION];		/* Default context (for transfer really) */
	
	int expire;					/* Schedule entry for expirey */
	int expirey;					/* How soon to expire */
	int capability;					/* Capability */
	char zonetag[80];				/* Time Zone */

	/* Qualification */
	int callno;					/* Call number of POKE request */
	int pokeexpire;					/* When to expire poke */
	int lastms;					/* How long last response took (in ms), or -1 for no response */
	int maxms;					/* Max ms we will accept for the host to be up, 0 to not monitor */
	
	struct ast_ha *ha;
	struct iax2_peer *next;
};

#define IAX2_TRUNK_PREFACE (sizeof(struct iax_frame) + sizeof(struct ast_iax2_meta_hdr) + sizeof(struct ast_iax2_meta_trunk_hdr))

static struct iax2_trunk_peer {
	ast_mutex_t lock;
	int sockfd;
	struct sockaddr_in addr;
	struct timeval txtrunktime;		/* Transmit trunktime */
	struct timeval rxtrunktime;		/* Receive trunktime */
	struct timeval lasttxtime;		/* Last transmitted trunktime */
	struct timeval trunkact;		/* Last trunk activity */
	unsigned int lastsent;			/* Last sent time */
	/* Trunk data and length */
	unsigned char *trunkdata;
	unsigned int trunkdatalen;
	unsigned int trunkdataalloc;
	struct iax2_trunk_peer *next;
	int trunkerror;
	int calls;
} *tpeers = NULL;

AST_MUTEX_DEFINE_STATIC(tpeerlock);

struct iax_firmware {
	struct iax_firmware *next;
	int fd;
	int mmaplen;
	int dead;
	struct ast_iax2_firmware_header *fwh;
	unsigned char *buf;
};

#define REG_STATE_UNREGISTERED	0
#define REG_STATE_REGSENT	1
#define REG_STATE_AUTHSENT 	2
#define REG_STATE_REGISTERED 	3
#define REG_STATE_REJECTED	4
#define REG_STATE_TIMEOUT	5
#define REG_STATE_NOAUTH	6

#define TRANSFER_NONE		0
#define TRANSFER_BEGIN		1
#define TRANSFER_READY		2
#define TRANSFER_RELEASED	3
#define TRANSFER_PASSTHROUGH	4

struct iax2_registry {
	struct sockaddr_in addr;		/* Who we connect to for registration purposes */
	char username[80];
	char secret[80];			/* Password or key name in []'s */
	char random[80];
	int expire;				/* Sched ID of expiration */
	int refresh;				/* How often to refresh */
	int regstate;
	int messages;				/* Message count */
	int callno;				/* Associated call number if applicable */
	struct sockaddr_in us;			/* Who the server thinks we are */
	struct iax2_registry *next;
};

static struct iax2_registry *registrations;

/* Don't retry more frequently than every 10 ms, or less frequently than every 5 seconds */
#define MIN_RETRY_TIME		100
#define MAX_RETRY_TIME  	10000

#define MAX_JITTER_BUFFER 	50
#define MIN_JITTER_BUFFER 	10

#define DEFAULT_TRUNKDATA	640 * 10	/* 40ms, uncompressed linear * 10 channels */
#define MAX_TRUNKDATA		640 * 200	/* 40ms, uncompressed linear * 200 channels */

#define MAX_TIMESTAMP_SKEW	160		/* maximum difference between actual and predicted ts for sending */

/* If consecutive voice frame timestamps jump by more than this many milliseconds, then jitter buffer will resync */
#define TS_GAP_FOR_JB_RESYNC	5000

/* If we have more than this much excess real jitter buffer, shrink it. */
static int max_jitter_buffer = MAX_JITTER_BUFFER;
/* If we have less than this much excess real jitter buffer, enlarge it. */
static int min_jitter_buffer = MIN_JITTER_BUFFER;

struct iax_rr {
	int jitter;
	int losspct;
	int losscnt;
	int packets;
	int delay;
	int dropped;
	int ooo;
};

struct chan_iax2_pvt {
	/* Socket to send/receive on for this call */
	int sockfd;
	/* Last received voice format */
	int voiceformat;
	/* Last received voice format */
	int videoformat;
	/* Last sent voice format */
	int svoiceformat;
	/* Last sent video format */
	int svideoformat;
	/* What we are capable of sending */
	int capability;
	/* Last received timestamp */
	unsigned int last;
	/* Last sent timestamp - never send the same timestamp twice in a single call */
	unsigned int lastsent;
	/* Next outgoing timestamp if everything is good */
	unsigned int nextpred;
	/* True if the last voice we transmitted was not silence/CNG */
	int notsilenttx;
	/* Ping time */
	unsigned int pingtime;
	/* Max time for initial response */
	int maxtime;
	/* Peer Address */
	struct sockaddr_in addr;
	struct ast_codec_pref prefs;
	/* Our call number */
	unsigned short callno;
	/* Peer callno */
	unsigned short peercallno;
	/* Peer selected format */
	int peerformat;
	/* Peer capability */
	int peercapability;
	/* timeval that we base our transmission on */
	struct timeval offset;
	/* timeval that we base our delivery on */
	struct timeval rxcore;
#ifdef NEWJB
	/* The jitterbuffer */
        jitterbuf *jb;
	/* active jb read scheduler id */
        int jbid;                       
#else
	/* Historical delivery time */
	int history[MEMORY_SIZE];
	/* Current base jitterbuffer */
	int jitterbuffer;
	/* Current jitter measure */
	int jitter;
	/* Historic jitter value */
	int historicjitter;
#endif
	/* LAG */
	int lag;
	/* Error, as discovered by the manager */
	int error;
	/* Owner if we have one */
	struct ast_channel *owner;
	/* What's our state? */
	int state;
	/* Expirey (optional) */
	int expirey;
	/* Next outgoing sequence number */
	unsigned char oseqno;
	/* Next sequence number they have not yet acknowledged */
	unsigned char rseqno;
	/* Next incoming sequence number */
	unsigned char iseqno;
	/* Last incoming sequence number we have acknowledged */
	unsigned char aseqno;
	/* Peer name */
	char peer[80];
	/* Default Context */
	char context[80];
	/* Caller ID if available */
	char cid_num[80];
	char cid_name[80];
	/* Hidden Caller ID (i.e. ANI) if appropriate */
	char ani[80];
	/* DNID */
	char dnid[80];
	/* Requested Extension */
	char exten[AST_MAX_EXTENSION];
	/* Expected Username */
	char username[80];
	/* Expected Secret */
	char secret[80];
	/* permitted authentication methods */
	int authmethods;
	/* permitted encryption methods */
	int encmethods;
	/* MD5 challenge */
	char challenge[10];
	/* Public keys permitted keys for incoming authentication */
	char inkeys[80];
	/* Private key for outgoing authentication */
	char outkey[80];
	/* Encryption AES-128 Key */
	aes_encrypt_ctx ecx;
	/* Decryption AES-128 Key */
	aes_decrypt_ctx dcx;
	/* 32 bytes of semi-random data */
	char semirand[32];
	/* Preferred language */
	char language[MAX_LANGUAGE];
	/* Hostname/peername for naming purposes */
	char host[80];
	/* Associated registry */
	struct iax2_registry *reg;
	/* Associated peer for poking */
	struct iax2_peer *peerpoke;
	/* IAX_ flags */
	unsigned int flags;

	/* Transferring status */
	int transferring;
	/* Transfer identifier */
	int transferid;
	/* Who we are IAX transfering to */
	struct sockaddr_in transfer;
	/* What's the new call number for the transfer */
	unsigned short transfercallno;
	/* Transfer decrypt AES-128 Key */
	aes_encrypt_ctx tdcx;

	/* Status of knowledge of peer ADSI capability */
	int peeradsicpe;
	
	/* Who we are bridged to */
	unsigned short bridgecallno;
	unsigned int bridgesfmt;
	struct ast_trans_pvt *bridgetrans;
	
	int pingid;			/* Transmit PING request */
	int lagid;			/* Retransmit lag request */
	int autoid;			/* Auto hangup for Dialplan requestor */
	int authid;			/* Authentication rejection ID */
	int authfail;			/* Reason to report failure */
	int initid;			/* Initial peer auto-congest ID (based on qualified peers) */
	int calling_ton;
	int calling_tns;
	int calling_pres;
	char dproot[AST_MAX_EXTENSION];
	char accountcode[AST_MAX_ACCOUNT_CODE];
	int amaflags;
	struct iax2_dpcache *dpentries;
	struct ast_variable *vars;
	/* last received remote rr */
	struct iax_rr remote_rr;
	/* Current base time: (just for stats) */
	int min;
	/* Dropped frame count: (just for stats) */
	int frames_dropped;
	/* received frame count: (just for stats) */
	int frames_received;
};

static struct ast_iax2_queue {
	struct iax_frame *head;
	struct iax_frame *tail;
	int count;
	ast_mutex_t lock;
} iaxq;

static struct ast_user_list {
	struct iax2_user *users;
	ast_mutex_t lock;
} userl;

static struct ast_peer_list {
	struct iax2_peer *peers;
	ast_mutex_t lock;
} peerl;

static struct ast_firmware_list {
	struct iax_firmware *wares;
	ast_mutex_t lock;
} waresl;

/* Extension exists */
#define CACHE_FLAG_EXISTS		(1 << 0)
/* Extension is nonexistent */
#define CACHE_FLAG_NONEXISTENT		(1 << 1)
/* Extension can exist */
#define CACHE_FLAG_CANEXIST		(1 << 2)
/* Waiting to hear back response */
#define CACHE_FLAG_PENDING		(1 << 3)
/* Timed out */
#define CACHE_FLAG_TIMEOUT		(1 << 4)
/* Request transmitted */
#define CACHE_FLAG_TRANSMITTED		(1 << 5)
/* Timeout */
#define CACHE_FLAG_UNKNOWN		(1 << 6)
/* Matchmore */
#define CACHE_FLAG_MATCHMORE		(1 << 7)

static struct iax2_dpcache {
	char peercontext[AST_MAX_CONTEXT];
	char exten[AST_MAX_EXTENSION];
	struct timeval orig;
	struct timeval expirey;
	int flags;
	unsigned short callno;
	int waiters[256];
	struct iax2_dpcache *next;
	struct iax2_dpcache *peer;	/* For linking in peers */
} *dpcache;

AST_MUTEX_DEFINE_STATIC(dpcache_lock);

static void reg_source_db(struct iax2_peer *p);
static struct iax2_peer *realtime_peer(const char *peername);

static void destroy_peer(struct iax2_peer *peer);
static int ast_cli_netstats(int fd, int limit_fmt);

static void iax_debug_output(const char *data)
{
	if (iaxdebug)
		ast_verbose("%s", data);
}

static void iax_error_output(const char *data)
{
	ast_log(LOG_WARNING, "%s", data);
}

#ifdef NEWJB
static void jb_error_output(const char *fmt, ...)
{
	va_list args;
	char buf[1024];

	va_start(args, fmt);
	vsnprintf(buf, 1024, fmt, args);
	va_end(args);

	ast_log(LOG_ERROR, buf);
}

static void jb_warning_output(const char *fmt, ...)
{
	va_list args;
	char buf[1024];

	va_start(args, fmt);
	vsnprintf(buf, 1024, fmt, args);
	va_end(args);

	ast_log(LOG_WARNING, buf);
}

static void jb_debug_output(const char *fmt, ...)
{
	va_list args;
	char buf[1024];

	va_start(args, fmt);
	vsnprintf(buf, 1024, fmt, args);
	va_end(args);

	ast_verbose(buf);
}
#endif


/* XXX We probably should use a mutex when working with this XXX */
static struct chan_iax2_pvt *iaxs[IAX_MAX_CALLS];
static ast_mutex_t iaxsl[IAX_MAX_CALLS];
static struct timeval lastused[IAX_MAX_CALLS];


static int send_command(struct chan_iax2_pvt *, char, int, unsigned int, const char *, int, int);
static int send_command_locked(unsigned short callno, char, int, unsigned int, const char *, int, int);
static int send_command_immediate(struct chan_iax2_pvt *, char, int, unsigned int, const char *, int, int);
static int send_command_final(struct chan_iax2_pvt *, char, int, unsigned int, const char *, int, int);
static int send_command_transfer(struct chan_iax2_pvt *, char, int, unsigned int, const char *, int);
static struct iax2_user *build_user(const char *name, struct ast_variable *v, int temponly);
static void destroy_user(struct iax2_user *user);
static int expire_registry(void *data);
static int iax2_write(struct ast_channel *c, struct ast_frame *f);
static int iax2_do_register(struct iax2_registry *reg);
static void prune_peers(void);
static int iax2_poke_peer(struct iax2_peer *peer, int heldcall);
static int iax2_provision(struct sockaddr_in *end, char *dest, const char *template, int force);

static struct ast_channel *iax2_request(const char *type, int format, void *data, int *cause);
static int iax2_devicestate(void *data);
static int iax2_digit(struct ast_channel *c, char digit);
static int iax2_sendtext(struct ast_channel *c, const char *text);
static int iax2_sendimage(struct ast_channel *c, struct ast_frame *img);
static int iax2_sendhtml(struct ast_channel *c, int subclass, const char *data, int datalen);
static int iax2_call(struct ast_channel *c, char *dest, int timeout);
static int iax2_hangup(struct ast_channel *c);
static int iax2_answer(struct ast_channel *c);
static struct ast_frame *iax2_read(struct ast_channel *c);
static int iax2_write(struct ast_channel *c, struct ast_frame *f);
static int iax2_indicate(struct ast_channel *c, int condition);
static int iax2_setoption(struct ast_channel *c, int option, void *data, int datalen);
static int iax2_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags, struct ast_frame **fo, struct ast_channel **rc);
static int iax2_transfer(struct ast_channel *c, const char *dest);
static int iax2_fixup(struct ast_channel *oldchannel, struct ast_channel *newchan);

static const struct ast_channel_tech iax2_tech = {
	.type = channeltype,
	.description = tdesc,
	.capabilities = IAX_CAPABILITY_FULLBANDWIDTH,
	.properties = AST_CHAN_TP_WANTSJITTER,
	.requester = iax2_request,
	.devicestate = iax2_devicestate,
	.send_digit = iax2_digit,
	.send_text = iax2_sendtext,
	.send_image = iax2_sendimage,
	.send_html = iax2_sendhtml,
	.call = iax2_call,
	.hangup = iax2_hangup,
	.answer = iax2_answer,
	.read = iax2_read,
	.write = iax2_write,
	.write_video = iax2_write,
	.indicate = iax2_indicate,
	.setoption = iax2_setoption,
	.bridge = iax2_bridge,
	.transfer = iax2_transfer,
	.fixup = iax2_fixup,
};

static int send_ping(void *data)
{
	int callno = (long)data;
	/* Ping only if it's real, not if it's bridged */
	if (iaxs[callno]) {
#ifdef BRIDGE_OPTIMIZATION
		if (!iaxs[callno]->bridgecallno)
#endif
			send_command(iaxs[callno], AST_FRAME_IAX, IAX_COMMAND_PING, 0, NULL, 0, -1);
		return 1;
	} else
		return 0;
}

static int get_encrypt_methods(const char *s)
{
	int e;
	if (!strcasecmp(s, "aes128"))
		e = IAX_ENCRYPT_AES128;
	else if (ast_true(s))
		e = IAX_ENCRYPT_AES128;
	else
		e = 0;
	return e;
}

static int send_lagrq(void *data)
{
	int callno = (long)data;
	/* Ping only if it's real not if it's bridged */
	if (iaxs[callno]) {
#ifdef BRIDGE_OPTIMIZATION
		if (!iaxs[callno]->bridgecallno)
#endif		
			send_command(iaxs[callno], AST_FRAME_IAX, IAX_COMMAND_LAGRQ, 0, NULL, 0, -1);
		return 1;
	} else
		return 0;
}

static unsigned char compress_subclass(int subclass)
{
	int x;
	int power=-1;
	/* If it's 128 or smaller, just return it */
	if (subclass < IAX_FLAG_SC_LOG)
		return subclass;
	/* Otherwise find its power */
	for (x = 0; x < IAX_MAX_SHIFT; x++) {
		if (subclass & (1 << x)) {
			if (power > -1) {
				ast_log(LOG_WARNING, "Can't compress subclass %d\n", subclass);
				return 0;
			} else
				power = x;
		}
	}
	return power | IAX_FLAG_SC_LOG;
}

static int uncompress_subclass(unsigned char csub)
{
	/* If the SC_LOG flag is set, return 2^csub otherwise csub */
	if (csub & IAX_FLAG_SC_LOG) {
		/* special case for 'compressed' -1 */
		if (csub == 0xff)
			return -1;
		else
			return 1 << (csub & ~IAX_FLAG_SC_LOG & IAX_MAX_SHIFT);
	}
	else
		return csub;
}

static struct iax2_peer *find_peer(const char *name, int realtime) 
{
	struct iax2_peer *peer;
	ast_mutex_lock(&peerl.lock);
	for(peer = peerl.peers; peer; peer = peer->next) {
		if (!strcasecmp(peer->name, name)) {
			break;
		}
	}
	ast_mutex_unlock(&peerl.lock);
	if(!peer && realtime)
		peer = realtime_peer(name);
	return peer;
}

static int iax2_getpeername(struct sockaddr_in sin, char *host, int len, int lockpeer)
{
	struct iax2_peer *peer;
	int res = 0;
	if (lockpeer)
		ast_mutex_lock(&peerl.lock);
	peer = peerl.peers;
	while(peer) {
		if ((peer->addr.sin_addr.s_addr == sin.sin_addr.s_addr) &&
				(peer->addr.sin_port == sin.sin_port)) {
					ast_copy_string(host, peer->name, len);
					res = 1;
					break;
		}
		peer = peer->next;
	}
	if (lockpeer)
		ast_mutex_unlock(&peerl.lock);
	return res;
}

static struct chan_iax2_pvt *new_iax(struct sockaddr_in *sin, int lockpeer, const char *host)
{
	struct chan_iax2_pvt *tmp;
	tmp = malloc(sizeof(struct chan_iax2_pvt));
	if (tmp) {
		memset(tmp, 0, sizeof(struct chan_iax2_pvt));
		tmp->prefs = prefs;
		tmp->callno = 0;
		tmp->peercallno = 0;
		tmp->transfercallno = 0;
		tmp->bridgecallno = 0;
		tmp->pingid = -1;
		tmp->lagid = -1;
		tmp->autoid = -1;
		tmp->authid = -1;
		tmp->initid = -1;
		/* ast_copy_string(tmp->context, context, sizeof(tmp->context)); */
		ast_copy_string(tmp->exten, "s", sizeof(tmp->exten));
		ast_copy_string(tmp->host, host, sizeof(tmp->host));
#ifdef NEWJB
		{
			jb_conf jbconf;

			tmp->jb = jb_new();
			tmp->jbid = -1;
			jbconf.max_jitterbuf = maxjitterbuffer;
			jbconf.resync_threshold = resyncthreshold;
			jbconf.max_contig_interp = maxjitterinterps;
			jb_setconf(tmp->jb,&jbconf);
		}
#endif
	}
	return tmp;
}

static struct iax_frame *iaxfrdup2(struct iax_frame *fr)
{
	/* Malloc() a copy of a frame */
	struct iax_frame *new = iax_frame_new(DIRECTION_INGRESS, fr->af.datalen);
	if (new) {
		memcpy(new, fr, sizeof(struct iax_frame));	
		iax_frame_wrap(new, &fr->af);
		new->data = NULL;
		new->datalen = 0;
		new->direction = DIRECTION_INGRESS;
		new->retrans = -1;
	}
	return new;
}

#define NEW_PREVENT 	0
#define NEW_ALLOW 	1
#define NEW_FORCE 	2

static int match(struct sockaddr_in *sin, unsigned short callno, unsigned short dcallno, struct chan_iax2_pvt *cur)
{
	if ((cur->addr.sin_addr.s_addr == sin->sin_addr.s_addr) &&
		(cur->addr.sin_port == sin->sin_port)) {
		/* This is the main host */
		if ((cur->peercallno == callno) ||
			((dcallno == cur->callno) && !cur->peercallno)) {
			/* That's us.  Be sure we keep track of the peer call number */
			return 1;
		}
	}
	if ((cur->transfer.sin_addr.s_addr == sin->sin_addr.s_addr) &&
	    (cur->transfer.sin_port == sin->sin_port) && (cur->transferring)) {
		/* We're transferring */
		if (dcallno == cur->callno)
			return 1;
	}
	return 0;
}

static void update_max_trunk(void)
{
	int max = TRUNK_CALL_START;
	int x;
	/* XXX Prolly don't need locks here XXX */
	for (x=TRUNK_CALL_START;x<IAX_MAX_CALLS - 1; x++) {
		if (iaxs[x])
			max = x + 1;
	}
	maxtrunkcall = max;
	if (option_debug)
		ast_log(LOG_DEBUG, "New max trunk callno is %d\n", max);
}

static void update_max_nontrunk(void)
{
	int max = 1;
	int x;
	/* XXX Prolly don't need locks here XXX */
	for (x=1;x<TRUNK_CALL_START - 1; x++) {
		if (iaxs[x])
			max = x + 1;
	}
	maxnontrunkcall = max;
	if (option_debug)
		ast_log(LOG_DEBUG, "New max nontrunk callno is %d\n", max);
}

static int make_trunk(unsigned short callno, int locked)
{
	int x;
	int res= 0;
	struct timeval now;
	if (iaxs[callno]->oseqno) {
		ast_log(LOG_WARNING, "Can't make trunk once a call has started!\n");
		return -1;
	}
	if (callno & TRUNK_CALL_START) {
		ast_log(LOG_WARNING, "Call %d is already a trunk\n", callno);
		return -1;
	}
	gettimeofday(&now, NULL);
	for (x=TRUNK_CALL_START;x<IAX_MAX_CALLS - 1; x++) {
		ast_mutex_lock(&iaxsl[x]);
		if (!iaxs[x] && ((now.tv_sec - lastused[x].tv_sec) > MIN_REUSE_TIME)) {
			iaxs[x] = iaxs[callno];
			iaxs[x]->callno = x;
			iaxs[callno] = NULL;
			/* Update the two timers that should have been started */
			if (iaxs[x]->pingid > -1)
				ast_sched_del(sched, iaxs[x]->pingid);
			if (iaxs[x]->lagid > -1)
				ast_sched_del(sched, iaxs[x]->lagid);
			iaxs[x]->pingid = ast_sched_add(sched, ping_time * 1000, send_ping, (void *)(long)x);
			iaxs[x]->lagid = ast_sched_add(sched, lagrq_time * 1000, send_lagrq, (void *)(long)x);
			if (locked)
				ast_mutex_unlock(&iaxsl[callno]);
			res = x;
			if (!locked)
				ast_mutex_unlock(&iaxsl[x]);
			break;
		}
		ast_mutex_unlock(&iaxsl[x]);
	}
	if (x >= IAX_MAX_CALLS - 1) {
		ast_log(LOG_WARNING, "Unable to trunk call: Insufficient space\n");
		return -1;
	}
	ast_log(LOG_DEBUG, "Made call %d into trunk call %d\n", callno, x);
	/* We move this call from a non-trunked to a trunked call */
	update_max_trunk();
	update_max_nontrunk();
	return res;
}

static int find_callno(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int lockpeer, int sockfd)
{
	int res = 0;